/ Dictionary / Index G giant kelp: Meaning and Definition of Find definitions for: gi'ant kelp' Pronunciation: [key] any of various very large kelps of the genera Laminaria, Macrocystis, and Nereocystis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. giantism giant lizard Related Content Daily Word Quiz: pudgy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language